A purple heart is a U.S. military decoration for soldiers
wounded or killed in battle.

Purple light,
At the warfront,
That is where,
My body lies,
If I die,
Will you B-U-R-Y me,
With my rifle and my buddy and me-ee-ee.

Hence the song....only those that are at the front line had a
chance to get a purple heart....for they may be the first to be
sacrificed...with the flashes of bullets ...the candlelights of
life extinguished and purple hearts are created.